Chemically protective articles with separable adsorptive liner

ABSTRACT

A chemically protective article comprising an outer shell and a separable adsorptive liner is provided. When the adsorption sites of the liner become saturated, the liner alone may be replaced without discarding the entire article. The liner also provides additional protection from harmful species should the outer shell be breached. Such chemically protective articles include garments, shelters, and coverings.

TECHNICAL FIELD

The present invention relates to a chemically protective garment,shelter, or covering comprising an outer shell and a separable linerthat contains adsorptive material. When the adsorption sites of theliner become saturated, the liner alone may be replaced withoutdiscarding the entire garment. The liner also provides additionalprotection from harmful species should the outer shell be breached.

BACKGROUND

Individuals who may come in contact with hazardous chemicals may weargarments utilizing a variety of technologies for protection depending onspecific needs. The garment may include a layer of a material likeactivated carbon that is capable of adsorbing hazardous vapors andliquids. Chemically protective garments based on activated carbon aredisclosed, for example, in U.S. Pat. No. 4,510,193. Air permeableprotective garments for military personnel that include a layercontaining activated carbon are described by, for example,Schreuder-Gibson et al. in MRS Bulletin 28(8), 574-578 (2003).Chemically protective garments containing both an adsorbent layer and asemipermeable membrane are disclosed, for example, in PCT Application WO2005049147. Chemically protective gloves containing both an adsorbentlayer and an impermeable layer are disclosed in, for example, U. S.Patent Application Publication 2007/0000017.

Activated carbon has a limited capacity, resulting in a significantreduction in protection once its adsorptive sites are saturated.Depending on the working environment, the adsorbing capability may besatisfactory for several months, or at the other extreme, for only a fewseconds or minutes if exposed to liquids or high vapor concentrations.

The present invention provides a chemically protective garmentcomprising an outer shell and a separable adsorptive liner that providesadditional protection from harmful species should the outer shell bebreached and that, when the adsorption sites of the liner becomesaturated, may be replaced by itself without discarding the entiregarment.

SUMMARY OF THE INVENTION

The present invention provides a chemically protective articlecomprising a shell and a separable liner wherein the separable linercomprises adsorptive material and wherein the chemically protectivearticle is a garment, shelter, or covering.

These and other aspects of the present invention will be apparent to oneskilled in the art in view of the following description and the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing front and back views of thestructure of a garment comprising one type of shell and separable lineraccording to an embodiment of the present invention.

DETAILED DESCRIPTION

In the context of this disclosure, a number of terms shall be utilized.

The term “membrane” as used herein denotes a discrete, thin structurethat moderates the transport of species in contact with it, such as gas,vapor, aerosol, liquid and/or particulates. Examples of membranesinclude without limitation film, plastic sheeting, synthetic barriers,layers, laminar structures, woven fabric, and nonwoven sheet.

The term “permeable” as used herein means allowing the passage ofliquids or gases.

The term “selectively permeable” as used herein means allowing passageof certain species but acting as a barrier to others.

The term “shell” or, equivalently, “outer shell” as used herein meansthe outermost layer of a finished article such as a garment.

The term “separable liner” as used herein denotes a liner that can bereadily attached to and detached from the shell.

The term “harmful to human health” as used herein means causing injuryto humans as a consequence of acute or chronic exposure through dermalcontact, ingestion, or respiration.

The term “polyester” as used herein means a condensation polymer inwhich more than 50 percent of the groups connecting repeat units areester groups. Thus polyesters may include polyesters, poly(ester-amides)and poly(ester-imides), so long as more than half of the connectinggroups are ester groups. The proportion of ester connecting groups canbe estimated to a first approximation by the molar ratios of monomersused to make the polyester.

The term “PET” as used herein the term means a polyester in which atleast 80, more preferably at least 90, mole percent of the diol repeatunits are from ethylene glycol and at least 80, more preferably at least90, mole percent of the dicarboxylic acid repeat units are fromterephthalic acid.

The term “PPT” as used herein means a polyester in which at least 80,more preferably at least 90, mole percent of the diol repeat units arefrom 1,3-propanediol and at least 80, more preferably at least 90, molepercent of the dicarboxylic acid repeat units are from terephthalicacid.

The term “polyamide” as used herein means a condensation polymer inwhich more than 50 percent of the groups connecting repeat units areamide groups. The proportion of amide connecting groups can be estimatedto a first approximation by the molar ratios of monomers used to makethe polyamide.

The term “nylon” as used herein means a polyamide other than an aramid.

The term “aramid” as used herein means an aromatic polyamide, wherein atleast 85% of the amide (—CONH—) linkages are attached directly to twoaromatic rings.

The term “modacrylic” as used herein means a polymer composed of lessthan 85% but at least 35% by weight of acrylonitrile.

The term “tricot” as used herein means a knit fabric formed byinterloping adjacent, parallel yarns.

The term “(co)polymers” as used herein means “homopolymers andcopolymers.”

The term “laminate” as used herein means a material comprising two ormore parallel layers of material that are at least partially bonded toeach other.

The term “continuous” as used herein to describe bonding between twoitems means that the entire surface area of one item is bonded to thesurface of the other item. The term “discontinuous” as used herein meansthat part of the surface area on one item is not bonded to the surfaceof the other item.

The term “reversible connecting means” as used herein indicates aconnecting means that can be used repeatedly to connect and disconnectitems together, without damaging either the items being connected or theconnecting means itself. Thus, a permanent glue would not be areversible connecting means, but a zipper or hook and loop fastenerwould.

The present invention provides a chemically protective articlecomprising an outer shell and a separable liner that comprisesadsorptive material. In one embodiment, the finished article furthercomprises a chemically protective membrane which may be essentiallyimpermeable or selectively permeable (“SPM”). Finished articles includechemically protective garments, shelters, and covers.

Separable Liner

The separable liner comprises an adsorbent material, that is, a materialcapable of adsorbing species against which protection is desired.Adsorbent materials may be inorganic, such as one or more of silica gel,alumina or other metal oxides, metal hydroxides, molecular sieves, andzeolites; or they may be organic, such as activated carbon. Regardlessof the composition of the adsorbent material, the surface area should bemaximized in order to minimize the weight of adsorbent that is needed.Activated carbon is a preferred adsorbent. The activated carbon may bein the form of powder, beads, granules, nanotubes, fiber, or cloth. Theactivated carbon may be attached to a woven or non-woven fabric ordistributed in a foam supported on a fabric. Woven or knit activatedcarbon cloth is a preferred form of adsorbent; one commerciallyavailable example is Zorflex® activated carbon cloth produced by CalgonCarbon Corporation (Pittsburgh, Pa., USA). Though the carbon cloth maybe used as a liner by itself, it is preferred to bond it to anotherlightweight woven or knit liner fabric such as a tricot. This increasesstrength and prevents direct contact between the activated carbon andthe wearer's skin, and, in a garment, minimizes transfer of carbonparticles to the wearer's skin. Bonding between the carbon cloth and theliner fabric may be continuous (i.e., the entire surface area of thecarbon cloth is bonded to the liner fabric) or discontinuous (i.e., somearea of the carbon cloth is not bonded to the liner fabric). Bonding isaccomplished by any appropriate connecting means used in the garmenttextiles industry, including without limitation adhesive, stitching,zippers, snaps, buttons, and string. Bonding by adhesives indiscontinuous patterns such as dots is preferred.

The adsorptive liner provides back-up protection in the event that theouter shell or the protective membrane is breached. In addition, in agarment which cannot be laundered or can be laundered only with greatdifficulty, the adsorptive liner is useful in adsorbing body odors

Furthermore, when the useful life of the liner approaches its endbecause of saturation of the adsorptive sites, the liner alone may bereplaced without discarding the entire garment. In some cases, the linermay be subjected to a process for regenerating the adsorptive capabilityand then rejoined to the garment. For example, the adsorptive capacityof a liner comprising activated carbon may be regenerated by as much as90 to 95% capacity by heating it under vacuum or exposing it to steam.

Outer Shell

The shell comprises woven fabric or non-woven fabric (e.g., nonwovensheet structures created by spun bonded/melt blown processes or byelectrospinning as described in, e.g., Z.-M. Huang et al., CompositesScience and Technology (2003), 63, 2223-2253). Shell fabrics may beprepared from any synthetic or natural fiber suitable for the intendedend use and are typically selected from the group consisting of nylons,cotton, polyesters, modacrylic, aramids, and blends containing any ofthese. One commonly used blend is a blend of nylon and cotton fibers(“NYCO”). Preferred polyesters are PET (co)polymers and blends and PPT(co)polymers and blends. A suitable aramid may be in the form of acopolymer that may have as much as 10 percent of other diamine(s)substituted for the diamine of the aramid or as much as 10 percent ofother diacid chloride(s) substituted for the diacid chloride of thearamid. A p-aramid would be preferred in a fabric as used in thisinvention, and poly(p-phenylene terephthalamide) (PPD-T) is thepreferred p-aramid. M-aramids may also find use in the presentinvention, and poly (m-phenylene isophthalamide) (MPD-I) is thepreferred m-aramid. P-aramid and m-aramid fibers and yarns particularlysuitable for use in the present invention are those sold respectivelyunder the trademarks Kevlar® and Nomex® (E. I. du Pont de Nemours andCompany, Wilmington Del., USA), and Teijinconex®, Twaron® and Technora®(Teijin Ltd., Osaka, Japan), and equivalent products offered by others.

The shell may further comprise a chemically protective membrane, or acomposite film or laminate that comprises a chemically protectivemembrane. The chemically protective membrane, composite film or laminatemay be bonded to the shell continuously or discontinuously usingadhesives, stitching, zippers, snaps, buttons, string, or otherconnecting devices common in the garment textiles industry. In oneexample of discontinuous bonding, the edges of the shell and achemically protective laminate are sewn together, an arrangement oftenreferred to as a “hung liner”. The use of adhesives in discontinuouspatterns such as dots is preferred.

Chemically Protective Membrane

The chemically protective membrane may be any of a variety known in themanufacture of chemically protective garments, shelters, and coveringsand is selected based on the nature of protection required.Additionally, the chemically protective membrane can extend the usefullife of the adsorptive liner by protecting it from many externaladsorbates.

In one embodiment, the chemically protective membrane is a selectivelypermeable membrane (“SPM”) that has a moisture vapor transport ratesufficient to promote the comfort of the wearer, while the transportrate of materials harmful to human health is low enough to prevent theoccurrence of injury, illness or death. The specific transport rateneeded will necessarily depend on standards for the specific harmfulsubstance; for example, NFPA 1994, 2006 Revision requires <4.0 μg/cm²one hour cumulative permeation for mustard and <1.25 μg/cm² for thenerve agent Soman. Permeability to specific harmful substances may bedetermined by various methods including, without limitation, thosedescribed in ASTM F739-91, “Standard Test Method for Resistance ofProtective Clothing Materials to Permeation by Liquids or Gases UnderConditions of Continuous Contact”; ASTM F903, “Standard Test Method forResistance of Protective Clothing Materials to Penetration by Liquids;”ASTM F1001 Chemical Test Battery; ASTM F1670, “Resistance of MaterialsUsed in Protective Clothing to Penetration by Synthetic Blood”; and ASTMF1671, “Resistance of Materials Used in Protective Clothing toPenetration by Blood-Borne Pathogens Using Phi-X174 BacteriophagePenetration as a Test System”.

SPM's useful in this embodiment may comprise any of a variety ofpolymers, including without limitation polyurethanes; polyether blockpolyamide copolymers (“PEBA”), polyether block polyester copolymers(“PEBE”); cellulose-based polymers; vinyl alcohol(co)polymers;perfluorinated sulfonic acid tetrafluoroethylene copolymers (such asNafion® perfluorosulfonic acid tetrafluoroethylene copolymer, availablefrom E. I. du Pont de Nemours and Company, Wilmington, Del., USA);highly fluorinated ion exchange polymer having sulfonic acid multivalentmetal ion salt functional groups, such as those described in U.S. Pat.No. 4,515,761; and those SPM's described in U.S. Pat. No. 5,391,426(crosslinked polyalkyleneimine wherein the alkylene moiety is 2 to 8carbon atoms); U.S. Pat. No. 5,824,405 (polyimides, especially5,5′-carbonylbis[1,3-isobenzofurandione], polymer with2,4-diisocyanato-1-methylbenzene and1,1′-methylenebis[4-isocyanatobenzene]) U.S. Pat. No. 6,395,383(polyamine polymer wherein at least 10% of the polyamine polymer aminesare amine-acid moieties wherein the acidic species of said amine-acidmoieties have a pK_(a) less than 6.4); U.S. Pat. No. 5,743,775(cellulose-based polymers); U.S. Pat. No. 6,792,625 (cellulose-basedpolymers, polytetrafluoroethylene, polyester, polyurethane); andapplications WO 2005/021100 A2 (sulfonated aromatic polymer comprisingat least one repeating aromatic group selected from 5,6, or 7-memberedsingle or fused rings having 0 to 4 heteroatoms selected from N, O or S,and at least a portion of the aromatic groups have at least one pendantgroup comprising sulfonic acid, or its salt); U.S. patent applicationSer. No. 11/079,121 (polyalkylamine in a polyurethane network), Ser. No.11/593,958 (chitosan and its derivatives), and Ser. No. 11/611,486 (acidpolysaccharides, including polysaccharides that contain acidicfunctional groups that are ionizable and salts of suchpolysaccharides.), all of which are hereby incorporated by reference intheir entirety.

In another embodiment, the chemically protective membrane allows vaportransport but is a barrier to liquid. Examples include withoutlimitation spun-bonded polyolefin, an example of which is DuPont™ Tyvek®spun-bonded olefin (E. I. du Pont de Nemours & Co., Inc., Wilmington,Del., USA); expanded polytetrafluoroethylene membranes such as thosesold under the trademark GORE-TEX® (W. L. Gore & Associates, Inc.,Newark, Del., USA); hydrophobic polyurethane microporous membranes (see,e.g., S. Brzeziński et al., Fibres & Textiles in Eastern Europe,January/December 2005, 13(6), 53-58); and microporous polypropyleneavailable from, e.g., 3M (St. Paul, Minn., USA).

In a further embodiment, the chemically protective membrane is largelyimpermeable to both water vapor and specific materials harmful to humanhealth. These impermeable membranes comprise polymer materials includingwithout limitation butyl rubber, tetrafluoroethylene (co)polymers,fluoroelastomers (e.g., Viton® fluoroelastomer, E.I. du Pont de Nemours& Co., Inc., Wilmington, Del., USA), polychloroprene, vinylidenechloride(co)polymers, PET film, metallized polymer film, vinylchloride(co)polymers, acrylic(co)polymers, acrylonitrile(co)polymers,and ethylene vinyl alcohol copolymers.

Chemically Protective Article Design

The design of the chemically protective articles of this invention islimited only by the capability for detaching and re-attaching theadsorptive liner to the shell. In a garment, the shape of the separableliner will generally conform to the shape of the shell in such a waythat most, if not all, portions of the body covered by the shell arelikewise covered by the separable liner. Attachment points between theshell and the liner will typically occur at the wrist, ankle, andneckline and near closures such as zippers. Other attachment points maybe desirable, for example in the seat or lower back, to maintainalignment of the liner with the shell. Attachment is accomplished by anyappropriate reversible connecting means including without limitationhook and loop fasteners such as VELCRO® brand fasteners (VelcroIndustries, B.V.), zippers, buttons, snaps, strings, and otherreversible closure devices.

To demonstrate one embodiment of the present invention, a one-pieceprotective garment with an integrated hood was made as illustrated byFIG. 1. The external shell was made of a woven blended fabric of nylon(50%) and cotton (50%) bonded to a PEBA film (13 μm thick) withpolyurethane adhesive dots. An attached butyl-rubber face-pieceinterface (hatched area 1 in front view) provided an interface for arespirator mask or the mask of a self-contained breathing apparatus(“SCBA”) on the hood. A single, long, chemical resistant, zipper (2)provided a means of donning and doffing the garment. An elastic stripwas attached inside the shell across the lower back (3 in back view) tohelp the garment conform more closely to the body. Cuffs at the wrist(hatched areas) (4) and ankles (5) were designed for interface withappropriate gloves and footwear. Strips of the “hook” portion of hookand loop fasteners were attached with adhesive inside the shell at thecuffs (shaded areas) (6), the legs (7), the neck (8), the zipper (9),the shoulders (10), and lower back (11). The separable liner conformedto the torso, arms and legs of the garment but did not include the hood.The liner was made of Zorflex® activated carbon cloth bonded to alightweight woven polyester fabric by means of polyurethane adhesivedots. Strips of the “loop” portion of “hook and loop fasteners” wereattached to the liner in conformance with their attachment points on theshell.

Many design variations are possible. For example, the separable linercould include coverage of the head by attachment to the inside of ahood, the arrangement of the zipper may be changed, and the glovesand/or footwear may include separable adsorptive liners.

Uses

The chemically protective garments, shelters, and protective covers ofthe present invention may be used to protect against harm or injury ascaused by exposure to toxic chemical and/or biological agents, includingwithout limitation those agents potentially used in a warfighterenvironment and materials identified as “Toxic Industrial Chemicals”(TICs) or “Toxic Industrial Materials” (TIMs); see, for example, Guidefor the Selection of Chemical and Biological Decontamination Equipmentfor Emergency First Responders, NIJ Guide 103-00, Volume I, published bythe National Institute of Justice, U.S. Department of Justice (October2001), herein incorporated by reference. A few examples of TICs arephosgene, chlorine, parathion, and acrylonitrile.

In one embodiment, the chemically protective garments, shelters, andchemically protective covers of the present invention are useful toprotect military personnel against dermal exposure to chemical andbiological agents potentially encountered in a warfighter environment.Examples of such agents include without limitation nerve agents such asSarin (“GB,” O-isopropyl methylphosphonofluoridate), Soman (“GD,”O-Pinacolyl methylphosphonofluoridate), Tabun (“GA,” O-EthylN,N-dimethylphosphoramidocyanidate), and VX (O-EthylS-2-diisopropylaminoethyl methylphosphonothiolate); vesicant agents suchas sulfur mustards (e.g., Bis(2-chloroethyl)sulfide andBis(2-chloroethylthio)methane); Lewisites such as2-chlorovinyldichloroarsine; nitrogen mustards such asBis-(2-chloroethyl) ethylamine (“HN1”); tear gases and riot controlagents such as Bromobenzyl cyanide (“CA”) and Phenylacyl chloride(“CN”); human pathogens such as viruses (e.g., encephalitis viruses,Ebola virus), bacteria (e.g., Rickettsia rickettsii, Bacillus anthracis,Clostridium botulinum), and toxins (e.g., Ricin, Cholera toxins). Ahuman pathogen is a microorganism that causes disease in humans.

In a further embodiment, the chemically protective garment of thepresent invention is useful to protect first responder personnel fromknown or unknown chemical or biological agents potentially encounteredin an emergency response situation. In yet another embodiment, thechemically protective garment is intended to protect cleanup personnelfrom chemical or biological agents during a hazmat response situation.Examples of hazardous material in addition to those listed above includecertain pesticides, particularly organophosphate pesticides.Furthermore, the chemically protective garment can be used in variousmedical applications as protection against toxic chemical and/orbiological agents.

In another embodiment, the chemically protective garment is an item ofouterwear or sportswear and the primary function of the adsorptive lineris to adsorb odor.

Such garments include without limitation coveralls, protective suits,coats, jackets, raingear, ski pants, gloves, socks, boots, shoe and bootcovers, trousers, hoods, hats, masks, and shirts.

In another embodiment, the chemically protective garments are medicalgarments for health care workers, such as medical or surgical gowns,gloves, slippers, shoe and boot covers, and head coverings.

Yet another embodiment of the present invention is a chemicallyprotective covering comprising a separable adsorptive liner, forexample, a tarpaulin, equipment cover, storage container cover, orsleeping bag.

A further embodiment of the present invention is a shelter comprising aseparable adsorptive liner. Examples include without limitation tents,chemically protective shelters designed for military use, safe rooms incommercial and residential buildings, clean rooms in which to performsurgical procedures, clean rooms in which to conduct activitiesrequiring high air purity such as computer chip fabrication, and storagesheds. Separable adsorptive liners could be used in temporary,soft-walled construction (i.e., wherein the wall material used toenclose a space is flexible plastic sheeting or fabric as opposed torigid materials such as “sheet rock” (wall board), wood, concrete, ormetal) or in permanent construction.

One example of a soft-walled shelter suitable for use in the presentinvention is a Chemical-Biological Protective Shelter developed for themilitary that a 300-square-foot semi-cylindrical airbeam-supported softshelter that can be inflated in four minutes and made fully operationalin less than 20 minutes.

Another shelter suitable for use in the present invention is a “TEMPERtent” (acronym for “The Tent, Extendable Modular Personnel”) a modular,soft-walled, aluminum framed supported tent made of vinyl coatedpolyester cloth, designed for military use. Modules can be combined invarious configurations and used for a variety of functions, such asincluding field feeding, latrines, administrative offices, shops,kitchens, shower/shave units and medical facilities. A protectiveseparable adsorptive liner could be attached to the inner surface of thetent.

Another shelter for military applications suitable for use in thepresent invention is an “ISO Shelter,” which is a cargo transportermodified to be utilized as a communications shelter, tool or maintenancekit, unit support van, or mobile command post, etc. A chemicallyprotective separable adsorptive liner could be attached to the innersurface of the shelter walls and roof.

Another shelter for military applications suitable for use in thepresent invention is a combat support hospital, for example, using “CPDEPMEDS” (acronym for “Chemically Protected Deployable Medical System”)equipment. This is an integrated facility combining TEMPER tents, ISOShelters, and covered passageways, any or all of which could incorporatethe separable adsorptive liner described here.

1. A chemically protective article garment, shelter, or chemicallyprotective covering comprising a shell and a separable liner, whereinthe separable liner comprises adsorptive material and wherein thechemically protective article is a garment, shelter, or covering.
 2. Thechemically protective article according to claim 1 wherein theadsorptive material comprises at least one member selected from thegroup consisting of silica gel, alumina, other metal oxides, metalhydroxides, molecular sieves, zeolites, and activated carbon.
 3. Thechemically protective article according to claim 2 wherein the activatedcarbon is in the form of powder, beads, granules, nanotubes, fiber, ornon-woven, woven or knit cloth.
 4. The chemically protective articleaccording to claim 3 wherein the activated carbon is attached to a wovenor non-woven fabric.
 5. The chemically protective article according toclaim 3 wherein the activated carbon is dispersed in a foam and the foamis supported on a fabric.
 6. The chemically protective article accordingto claim 3 wherein the non-woven, woven or knit carbon cloth is bondedto another woven or knit fabric by a connecting means.
 7. The chemicallyprotective article according to claim 6 wherein the connecting means isselected from the group consisting of adhesive, stitching, zippers,snaps, buttons, and string.
 8. The chemically protective articleaccording to claim 7 wherein the connecting means is a discontinuouspattern of dots of adhesive.
 9. The chemically protective articleaccording to claim 1 wherein the separable liner is attached to theshell by a reversible connecting means.
 10. The chemically protectivearticle according to claim 9 wherein the reversible connecting means isselected from the group consisting of hook and loop closures, zippers,buttons, and snaps.
 11. The chemically protective article according toclaim 1 wherein the shell comprises a woven or non-woven fabric.
 12. Thechemically protective article according to claim 11 wherein the woven ornon-woven fabric is selected from the group consisting of nylons,cotton, polyesters, modacrylic, aramids, and blends containing any ofthese.
 13. The chemically protective article according to claim 1further comprising a chemically protective membrane.
 14. The chemicallyprotective article according to claim 13 wherein the chemicallyprotective membrane is a selectively permeable membrane.
 15. Thechemically protective article according to claim 14 wherein theselectively permeable membrane comprises a polymer selected from thegroup consisting of polyurethanes; polyether block polyamide copolymers:polyether block polyester copolymers; cellulose-based polymers; vinylalcohol(co)polymers; perfluorinated sulfonic acid tetrafluoroethylenecopolymers; highly fluorinated ion exchange polymer having sulfonic acidmultivalent metal ion salt functional groups, crosslinkedpolyalkyleneimine wherein the alkylene moiety is 2 to 8 carbon atoms;polyimides; polyamine polymer wherein at least 10% of the polyaminepolymer amines are amine-acid moieties wherein the acidic species ofsaid amine-acid moieties have a pK_(a) less than 6.4;polytetrafluoroethylene, polyesters; sulfonated aromatic polymercomprising at least one repeating aromatic group selected from 5,6, or7-membered single or fused rings having 0 to 4 heteroatoms selected fromN, O or S, and at least a portion of the aromatic groups have at leastone pendant group comprising sulfonic acid, and its salt; polyalkylaminein a polyurethane network; chitosan and its derivatives; acidpolysaccharides, including polysaccharides that contain acidicfunctional groups that are ionizable and salts of such polysaccharides.16. The chemically protective article according to claim 13 wherein thechemically protective membrane is selected from the group consistingspun-bonded polyolefin, expanded polytetrafluoroethylene membranes,hydrophobic polyurethane microporous membranes, and microporouspolypropylene.
 17. The chemically protective article according to claim13 wherein the chemically protective membrane comprises polymer materialselected from the group consisting butyl rubber,tetrafluoroethylene(co)polymer film, fluoroelastomers, polychloroprene,vinylidene chloride(co)polymers, poly(ethylene terephthalate) film,metallized polymer film, vinyl chloride(co)polymers,acrylic(co)polymers, acrylonitrile (co)polymers, and ethylene vinylalcohol copolymers.
 18. The chemically protective garment according toclaim 1 wherein the chemically protective garment is selected from thegroup consisting of coveralls, chemically protective suits, coats,jackets, raingear, ski pants, gloves, socks, boots, shoe or boot covers,trousers, hoods, hats, masks, shirts; and medical garments selected fromthe group consisting of medical and surgical: gowns, gloves, slippers,shoe and boot covers, and head coverings.
 19. The chemically protectivecovering according to claim 1 wherein the chemically protective coveringis selected from the group consisting of tarpaulins, equipment covers,storage container covers, and sleeping bags.
 20. The shelter accordingto claim 1 wherein the shelter is selected from the group consisting oftents, chemically protective shelters designed for military use, saferooms, clean rooms, and storage sheds.
 21. The chemically protectiveshelter designed for military use according to claim 20 wherein thechemically protective shelter is a combat hospital, modular tent,covered passageway, or ISO Shelter.
 22. The chemically protectiveshelter according to claim 20 wherein said shelter is soft-walled.